Search results for "Database"

A Two-layer Partitioning for Non-point Spatial Data

2021

Non-point spatial objects (e.g., polygons, linestrings, etc.) are ubiquitous and their effective management is always timely. We study the problem of indexing non-point objects in memory. We propose a secondary partitioning technique for space-oriented partitioning indices (e.g., grids), which improves their performance significantly, by avoiding the generation and elimination of duplicate results. Our approach is novel and of a high impact, as (i) it is extremely easy to implement and (ii) it can be used by any space-partitioning index. We show how our approach can be used to boost the performance of spatial range queries. We also show how we can avoid performing the expensive refinement s…

PASSIM – an open source software system for managing information in biomedical studies

2007

Abstract Background One of the crucial aspects of day-to-day laboratory information management is collection, storage and retrieval of information about research subjects and biomedical samples. An efficient link between sample data and experiment results is absolutely imperative for a successful outcome of a biomedical study. Currently available software solutions are largely limited to large-scale, expensive commercial Laboratory Information Management Systems (LIMS). Acquiring such LIMS indeed can bring laboratory information management to a higher level, but often implies sufficient investment of time, effort and funds, which are not always available. There is a clear need for lightweig…

IFC and Buildings Lifecycle Management

2008

International audience; This paper presents an extension of the BIM technology that allows to manage information during the entire lifecycle of an AEC project. Usually, AEC projects and facility management are dissociated. Our building information system plays a central role in the improvement of the design and the management process. The building activity generates a great number of data and information of various kinds. The management and the communication of these data by the various participants is complex. Our design and management methods use IFC files to facilitate the sharing process for a better qualification and validation of data.

Errors and Complications in SQL Query Formulation

2018

SQL is taught in almost all university level database courses, yet SQL has received relatively little attention in educational research. In this study, we present a database management system independent categorization of SQL query errors that students make in an introductory database course. We base the categorization on previous literature, present a class of logical errors that has not been studied in detail, and review and complement these findings by analyzing over 33,000 SQL queries submitted by students. Our analysis verifies error findings presented in previous literature and reveals new types of errors, namely logical errors recurring in similar manners among different students. We…

Distributed Coverage of Ego Networks in F2F Online Social Networks

2016

Although most online social networks rely on a centralized infrastructure, several proposals of Distributed Online Social Networks (DOSNs) have been recently presented. Since in DOSNs user profiles are stored on the peers of the users belonging to the network, one of the main challenges comes from guaranteeing the profile availability when the owner of the data is not online. In this paper, we propose a DOSN based on a friend-to-friend P2P overlay where the user's data is stored only on friend peers. Our approach is based on the ego-network concept, which models the social network from the local point of view of a single user. We propose a distributed algorithm which is based on the notion …

Contributions from ADBIS 2018 workshops

2018

The ADBIS conferences provide an international forum for the presentation of research on database theory, development of advanced DBMS technologies, and their applications. The 22nd edition of ADBIS, held on September 2–5, 2018, in Budapest, Hungary, includes six thematic workshops collecting contributions from various domains representing new trends in the broad research areas of databases and information systems.

Schema-Based Visual Queries over Linked Data Endpoints

2019

We present the option to use the schema-based visual query tool ViziQuer over realistic Linked Data endpoints. We describe the tool meta-schema structure and the means for the endpoint schema retrieval both from an OWL ontology and from a SPARQL endpoint. We report on a store of the endpoint-specific schemas and the options to support the schema presentation to the end-user both as a class tree within the environment and as external visual diagram.

Export of Relational Databases to RDF Databases: A Case Study

2010

The vast amount of business information nowadays is stored in relational databases. For the Semantic Web vision to become a reality, we need ways how to exploit this data in form of RDF triples. The universal and commonly accepted solution for this problem still does not exist. In most cases, mapping languages are used for specification of correspondences between OWL ontology and DB schema. At the same time, these languages generally are not well suited for specification of mappings in cases when there is a substantial difference between OWL ontology and DB schema. In this paper, we describe a new model transformation-based method for specification of correspondences between the elements of…

Databases and Information Systems

2001

A systematic analysis of duplicate records in Scopus

2015

In recent years, the Web of Science Core Collection and Scopus databases have become primary sources for conducting studies that evaluate scientific investigations. Such studies require that duplicate records be excluded to avoid errors of overrepresentation. In this line, we identify duplicate records in Scopus and examine their origins. Identifying journals with duplicate records in Scopus, selecting and downloading bibliographic journal records, and identifying and analyzing the duplicate records is the methodology adopted. Duplicate records are found when articles published in a journal are incorrectly mapped by Scopus to this journal and to a different journal from the same publisher a…